Just a tip in case any body has this issue.
I don't normally like touchpads but when travelling their use is sometimes unavoidable.
Anyway I just couldn't get mine on an ACER ASPIRE ONE netbook to work on Windows 7 -- installed new driver
etc etc which was not required at all.
Anyway I eventually found a really obscure old post that says sometimes you need to press Fn + F7 to get the touchpad working as this key combination toggles it on and off
Hope this might be of use to others where their touchpad doesn't work (or conversely if they want to disable it temporarily).